1. Field of the Invention
This invention relates to a case for storing a tape cassette and, more particularly, to a case having an inner case or slip which receives or partly envelopes the cassette and which is slidably inserted with the latter into an outer case.
2. Description of Known Structures
Tape cassettes are usually stored in a case when not in use to protect the cassette from dust and damage. The cassettes are often used frequently, however, so that it is particularly desirable for the cassettes to be easily removed and replaced in their respective cases.
There have been many attempts at providing a case for storing a tape cassette which properly protects the cassette but permits it to be easily removed and replaced. One known cassette case comprises a box-like outer case having an opening for receiving an inner case with the cassette therein. The inner case comprises a cardboard sheet folded in a U-shape to define a side member and opposite top and bottom panel members which are disposed against corresponding side, top and bottom surfaces of the cassette. The side member of the inner case is disposed in the opening into the outer case when the cassette and inner case are stored therein to cover at least the portion of the cassette which would otherwise be exposed by the opening.
In order to remove the inner case and cassette from the outer case, edges of the top and bottom walls of the outer case along the opening have thumb-size arcuate cutouts. The corresponding exposed portions of the top and bottom panel members of the stored inner case can then be gripped to pull the cassette and inner case from the outer case. Inasmuch as the inner case only extends in its U-shape along three sides of the cassette, however, and because the exposed portions of the inner case are only thumb-sized, the frictional engagement between the inner case and the cassette is often insufficient to withdraw the cassette from the outer case with the inner case. As a result, the inner case may be pulled from the outer case, while the cassette itself remains in the outer case. A second attempt to remove the cassette from the outer case is then required and, sometimes, the outer case had to be shaken or stretched in order to dislodge the cassette.
It has therefore been proposed to configure a substantial portion of the opposite edges of the outer case along the opening concavely of the outer case, preferably in a chevron. The concave chevron exposes a substantial portion of the inner case so that the inner case can be more firmly gripped for more assuredly removing the cassette from the outer case with the inner case.
When it is desired to replace the cassette in the case, the cassette is placed in the inner case and the inner case and cassette are then slid into the outer case through the opening. Free edges of the top and bottom panel members of the inner case remote from the side member thus have to slip past the corresponding edges of the outer case along the opening. If the free edges of the top and bottom panel members of the inner case are parallel to the corresponding edges of the outer case, then, as the cassette and inner case are being slidably inserted, the edges have to pass each other all along their lengths at once. In such case, the edges can easily catch on each other to prevent the easy insertion of the inner case and cassette into the outer case, particularly if one of the panel members does not lie flush with the adjacent surface of the cassette.
It has been proposed to avoid this problem by forming the panel members of the inner case with V-shaped free edges. However, such V-shaped free edges and the thumb-sized arcuate cutouts in the edges of the outer case along the opening are symmetrically arranged, so that the apex of each V-shaped edge is aligned with a respective arcuate cutout. Symmetrically opposite edge portions of the V-shaped edge of a panel member then have to simultaneously pass opposite portions of the respective arcuate cutout. Although the V-shaped panel member edge is no longer engageable with the corresponding edge of the outer case along a line, each V-shaped edge still has to simultaneously pass two points on the edge of the outer case. Thus, the inner case and cassette are still relatively difficult to insert in the outer case. Moreover, the corners where the arcuate indentation or cutout joins the remaining edge portion of the outer case along the opening often became damaged or burred by repeated engagements with the edge of the panel members to further impede smooth insertion of the inner case and cassette into the outer case.
In the existing cases in which edge portions of the outer case are chevron-shaped, the panel members of the inner case have straight free edges. Thus, the straight edges on the panel members still simultaneously pass the chevron-shaped edges of the outer case at two symmetrically opposite points when the inner case is inserted into the outer case. Although this arrangement is an improvement over the thumb-sized indentations or cutouts for removing the cassette and inner case from the outer case, it does not facilitate insertion of the inner case and cassette into the outer case.